The present invention relates to pipe couplings. Numerous coupling systems have been developed which have sought to allow shifting or moving of joining pipe sections with respect to one another. One group of pipe joints utilizes pipe ends having mating spherical surfaces for permitting slight misalignment of the pipe section along the joint. This arrangement can be characterized as a ball-and-socket pipe connection. These ball-and-socket type connections use both internal and external seals. Generally, these connections require separate external clamps or collars to join together the pipe sections and thus are not well suited for joining sewer or other large pipe sections.
The most prevalently used pipe joint for sewer conduit or other large concrete pipe is the insertion of the male end of one pipe into a receiving female or bell end in the other pipe. Another type are those which are formed by joining male or female ends of pipe sections with a coupler. As seen in FIGS. 8-10, such joints may be formed without requiring clamps. As seen, particularly in FIG. 10, the seals used in forming the joint are sometimes caught and unseated by the ends of the pipe sections when the joint is formed. The seals in such pipe serve a support function as well as a sealing function. Also, the pipe joint, thus formed, allows only slight movement of the pipe ends and coupler with respect to each other.